BIO120H1 Lecture Notes - Lecture 4: Genetic Variation, Dna Replication, Mendelian Inheritance
36
BIO120H1 Full Course Notes
Verified Note
36 documents
Document Summary
Requirements for darwin"s theory: variation, heredity, selection. A unit of hereditary information located on the chromosomes consisting of dna. A dna sequence composed of codons essential for a specific biological function. Codons: 3 nucleotides that make up the genetic code. Genetic variation comes from: mutation (ultimate source of genetic variation, recombination, gene flow, hybridization. Homeotic mutation: structures change position, example: leg where the antenna should be. Mcclintock: jumping genes discovery, jump around the genome (transposable genetic elements) Selection would take the mutation out (in the example of a mutant in the field) The bright flower would be visited more frequently and the mutation would be passed on and would spread through the population, and a new wild type is formed. So there are 2 possibilities: 1) the eradication of the mutation. Mutation: change in the dna sequence = change in genotype, occurs at a low variable rate, effects: neutral, deleterious, lethal, beneficial, fitness effects depends on the.
